摘要:

AbstractExperiments were conducted to examine the effects of ‘binge’ oracutematernal alcohol intoxication during the early proliferative phase of embryonic brain development. Primiparous mice received ethanol as 0, 10, 15 or 20% (v/v) aqueous solutions by gavage on days 13, 14 and 15 of gestation. Mean daily doses were 0.0, 2.58, 4.03 and 5.40 ml/kg, respectively. There was no alcohol‐related reduction in fetal body weight, length or fixed brain weight. Coronal sections (1 μm) of the dorsal roof of the lateral ventricles over the optic chiasma were examined from nine embryonic day 15 brains for each treatment group. The ventricular surface index of mitotic figures, the number and distribution of non‐surface mitotic figures, and the depth of the cortical roof and its constituent layers were determined. There was no alcohol‐related difference in any of these parameters. These results are in contrast to those of a previous experiment using the same mouse strain, in which prolonged orchronicmaternal alcohol consumption in the drinking water from days 11 to 19 of pregnancy was associated with a reduction in the surface index, a reduction in the depth of the cortical roof and an increase in the non‐surface mitotic figures. These latter changes, however, occurred in the presence of reduced body weight. Our observations suggest that during this particular developmental period (corresponding to the second trimester of human pregnancy) alcohol‐related reductions in brain growth parallel restrictions in general body growth.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90063-2

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractA method for the determination of putreanine has been developed, based on the separation of ion pairs with octanesulfonic acid on a reversed phase column. The method has been used to determine the developmental pattern of this amino acid in chick and rat brain.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90064-4

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe tuberous organs—cutaneous electroreceptors of the mormyrid fishBrienomyrus niger—were examined, with the light and electron microscope, after sectioning of the afferent nerve of the lateral line. Transection of the afferent nerve leads to the concomitant complete degeneration of all sensory cells, and to a differentiation of new sensory cells from accessory cells, which constitute the platform. Ultrastructural examination of the newly formed sensory cells shows that within a few days these gain the characteristics of normal sensory cells. The rapidly growing cytoplasm is enclosed in a folded membrane; the foldings develop typical dense microvilli. At the same time, in spite of lack of innervation, synaptic bars surrounded by vesicles differentiate in the cytoplasm; these are opposed to the basal cell membrane which is attached to the accessory cell platform. The newly formed sensory cells never reach the size of normally developed sensory cells. Their existence is transitory, for they degenerate, together with the sensory cells, one month after de‐afferentiation.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90065-6

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractMurine muscular dystrophy is characterized by a reduction of the 10S molecular form of acetylcholinesterase (AChE); this reduction occurs in both strains of dystrophic mice and at the time of the phenotypic appearance of the disease.In the present study we have analyzed the biochemical features, the cellular distribution and the developmental appearance of the AChE alteration. Sequential extractions with low salt, detergent and high salt revealed that this alteration affects only membrane‐bound forms (those requiring Triton X‐100 for solubilization), while both the low salt soluble and the high salt soluble forms appeared almost identical in normal and dystrophic muscles. Specific activity, sensitivity to different ions, pH dependence andKmwere found to be identical in the enzymes from normal and dystrophic muscles, suggesting that the catalytic site of the 10S form is probably not altered.Further analysis, by non‐denaturing gel electrophoresis, of the detergent soluble forms separated by sedimentation, revealed a single band for the 4S, a doublet for the 6S and three bands for the 10S peaks, indicating the existence of charge heterogeneity in AChE molecular forms. The corresponding molecular forms from dystrophic muscles behaved identically upon electrophoresis: the residual activity in the detergent soluble 10S form could still be separated into three bands, comigrating with their normal counterparts. Neuraminidase treatment resulted in a reduction of migration of both the 6S and 10S derived bands, but not of the 4S species, showing that sialic acid is added only to polymeric forms. Interestingly, the reduction of the 10S form appears to be linked to a developmental stage not reached in cell cultures, as cultured myotubes from muscles of dystrophic mice contained normal amounts of membrane‐bound AChE forms. The molecular mechanism underlying the reduction of the tetrameric membrane bound AChE form in dystrophic muscle and the possible functional consequences are discussed.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90066-8

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractCultures of isolated neurons have been treated with a purified preparation of gangliosides (10−5M and 10−9M) added to the cell growth medium at the 3rd day in culture and a morphometric analysis of the cells was performed with an image analyzer after 1 and 4 days of treatment. The number of cells and the area of the cell bodies were increased following the treatment. The results indicate as well the ‘sprouting’ effect of the glycolipids on the number of secondary neuronal processes and an increase in the length of the primary neuntes. The present data and other biochemical evidence (Dreyfuset al., 1984,J. Neurosci. Res.) suggest that the addition of exogenous gangliosides may have a trophic effect on neurons, greatly enhances the number of cell to cell contacts, and, possibly, stimulates cell proliferation and differentiation.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90067-X

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractCytoskeletal preparations containing both the glial fibrillary acidic protein and the neurofilament triplet proteins were prepared from brain stems of rats at different ages and the individual peptides separated in polyacrylamide gels. Stained peptide bands were quantitated as the area under peaks generated by densitometric scanning. Peak areas were converted to grams of protein based on total gel dye binding and total protein applied to the gels. Between 5 and 30 days, the concentration of the peptide (g of peptide/mg of tissue protein) of apparent molecular weight 51,000 (corresponding to the glial fibrillary acidic protein), increased 3 fold. The corresponding increase in total concentration of the three peptides corresponding to the neurofilament proteins was 4.5 fold. However, the increase in concentration of the individual neurofilament peptides was each different. Very little of the apparent molecular weight 210,000 neurofilament peptide was present at 5 days and its concentration increased 11 fold by 30 days compared to about 3.5 fold for the other two neurofilament peptides. These results are in general agreement with studies using immunological techniques and the methods have the advantages of using readily available techniques and allowing the simultaneous comparison of both neuronal and glial specific filaments during development.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90068-1

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractMicrotubules and neurofilaments were counted in cross‐sections of the sciatic nerve fibres of young rats at various stages of development. A linear relationship was found between the numbers of microtubules and neurofilaments and the size of the fibre. The number of microtubules progressively increased during the first two postnatal weeks. Neurofilaments appeared slightly later than microtubules. In thyroid deficiency, the number of microtubules was diminished. The number of neurofilaments was not markedly affected. The ratio of neurofilaments to microtubules was thus increased. The severe retardation of sciatic nerve growth observed in thyroid deficiency might be related to the reduced number of microtubules and to a diminution in fibre plasticity induced by the higher neurofilament to microtubule ratio.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90069-3

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe specific activity profiles of the glutamate synthesizing enzymes, phosphate activated glutaminase (EC 3.5.1.2), aspartate aminotransferase (EC 2.6.1.1), glutamate dehydrogenase (EC 1.4.1.2) and ornithine aminotransferase (EC 2.6.1.13) have been followed postnatally for 28 days in mouse hippocampus and compared to corresponding profiles in cerebellum and cerebral cortex (cf. refs 10 and 18). Phosphate activated glutaminase and glutamate dehydrogenase showed activity patterns similar to those found for cerebellum and glutamatergic granula cells cultured from cerebellum, whereas the aspartate aminotransferase activity pattern was found to be more similar to that previously observed for cerebral cortex as well as cultured cerebral interneurons which are likely to be GABAergic. The specific activity of ornithine aminotransferase was essentially unaltered during postnatal development, which is similar to what has been found for cerebellum and cerebral cortex.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90070-X

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractPurkinje cell bodies and dendrites in the chick embryo stained intensely by immunofluorescence and by the Avidin‐Biotin Complex (ABC) method using monoclonal and polyclonal antibodies to the neurofilament (NF) proteins. On day 20 (the day before hatching) NF immunoreactivity markedly decreased concomitant with the first appearance of NF‐positive basket axons in the molecular and Purkinje cell layers. On postnatal day 3, as in mature avian cerebellum, NF‐negative Purkinje cells were surrounded by NF‐positive baskets. Cytoplasmic 10 nm filaments were not observed in immature and mature Purkinje cells by electron microscopy. Basket axons in the hen were packed with 10 nm filaments.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90071-1

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe regional distribution of pipecolic acid and proline was studied in the adult and newborn rat brain. The brain concentration of pipecolic acid in the 1 and 3‐day‐old rat was 6–10 times higher than in the adult. The brain concentration of proline was found to be about 3 times higher in the brain of a newborn rat than in the adult, then it gradually decreased during the period of lactation. In plasma as well as in peripheral tissues, such as heart, kidney and liver, the highest concentration of pipecolic acid was observed at 1 day and in the adult. Secretion of pipecolic acid into the urine was highest at early stages of development. In the gastrointestinal tract, pipecolic acid was found to be most abundant in the adult, whereas low levels were found during the period of lactation. The developmental and regional changes in concentration of proline were quite different from those of pipecolic acid. Our results suggest that the contribution of dietary pipecolic acid in building up levels of pipecolic acid in rat brain is small.

ISSN:0736-5748    

DOI:10.1016/0736-5748(85)90072-3

出版商:Wiley    

年代:2003

数据来源: WILEY